#include <iostream>

using namespace std;
typedef long long LL;

const int N = 1e5 + 10;
int n,q;
LL a[N];
LL f[N]; //前缀和数组

int main()
{
    cin >> n >> q;
    for(int i = 1;i <= n; i++)
    {
        cin >> a[i];
    }
    //处理前缀和数组
    for(int i = 1;i <= n;i++)
    {
        f[i] = f[i - 1] + a[i];
    }

    while(q--)
    {
        int l,r;
        cin >> l >> r;
        cout << f[r] - f[l - 1] << endl;
    }
    return 0;
}